I recently traded in my perfectly maintained 02 Accord (5 speed) for this 99 A4 (5 speed too). The Accord was a great car but a bit boring. Never gave any trouble (with 75000 miles), was great on gas and was a good overall car. But then again it was a bit slow, and never gave me any major thrill.
I found this A4 with 75000 miles (low for the year) and with good sticker price. So I basically traded my Honda plus few hundreds for the Audi.
So far the car has been what I expected, a fast, tight and great handling compact sedan. But then again it is a hog for maintenance. Right after I got it, I replaced myself:
All timing gear, including belts, rollers, tensioners, coolant, thermostat, gaskets, water pump etc.. (a $2000 job at the dealer, a $300 job for you)
Front and rear brakes ($800 for dealer, $250 for you).
Filters, oils, spark plugs ($350 dealer, $100 for you), and a lot of leather care product for the S4 seats the car came with (priceless).
So far the car has been good, handles like it is glued to the road, ride is sporty but not harsh and fuel consumption never goes beyond 25 mpg. Interior makes you feel rich and famous. S4 seats are awesome. Power pulls nice from below all the way to the 6K mark, you can tell it uses all its 190 ponies.
I would recommend this car if you are into handling and European cars and most importantly can do a lot of maintenance and services by yourself. If you are not a DIY person, have a few thousands in your wallet to give away to the mechanics. Remember, parts are somewhat cheap, labor on this cars is stratospherically expensive.
If you want something classy but more reliable or that doesn't require so much maintenance go for the Lexus, Infinity, Acura or Mercedes.
But then again If you are the type of man who enjoys working and fixing your car as much as I do, go and get this car with either the V6 or the 1.8 Turbo, just make sure you have three pedals on the floor.